Method of obtaining a cellulosic textile fabric with reduced tendency to pilling formation

ABSTRACT

A method for obtaining a cellulosic textile fabric having a strongly reduced tendency to pilling formation, preferably corresponding to a pilling note of at least 4, more preferably of at least 4.5, which method comprises treating the fabric with a cellulase capable of performing a partial hydrolysis of the fibre surface corresponding to a &lt;2% weight loss based on the untreated cellulosic textile fabric. The cellulase is preferably a 43 kD endoglucanase derived from or producible by Humicola insolens, DSM 1800, SEQ ID NO:1, or a functional analogue of said cellulase such as a variant which is modified by substitution of one or more amino acid residues in one or more of the positions 8, 55, 58, 62, 67, 132, 147, 162, 221, 222, 223, 280; or modified by truncation, preferably genetically truncation, at any position from position 213.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. 371 national application ofPCT/DK95/00488 filed Dec. 5, 1995 and claims priority under 35 U.S.C.119 Danish application 1387/94 filed Dec. 5, 1994, the contents of whichapplications are fully incorporated herein by reference.

The present invention relates to a method for obtaining a cellulosictextile fabric having a strongly reduced tendency to pilling formation.More specifically, the invention relates to a method wherein thecellulosic textile fabric is subjected to an enzymatic treatment with acellulase without substantial weight loss.

BACKGROUND OF THE INVENTION

Without the application of finishing components, most cotton fabrics andcotton blend fabrics have a handle appearance that is rather hard andstiff. The fabric surface also is not smooth because small fuzzymicrofibrils protrude from it. In addition, after a relatively shortperiod of wear, pilling appears on the fabric surface thereby giving itan unappealing, worn look.

A known method for obtaining a soft and smooth fabric is to subjectcellulosic fabrics to treatment by cellulolytic enzymes during theirmanufacture. This treatment is known as Bio-Polishing (hereinafterdenoted biopolishing), cf. Bazin j. and Sasserod, S.: EnzymaticBio-Polishing of Cellulosic Fabric, Paper presented on Oct. 25th, 1991,at "58eme Congres de l'Association des Chimistes de l'IndustrieTextile", Mulhouse, France, which is hereby incorporated by reference.

Biopolishing is a specific treatment of the yarn surface which improvesfabric quality with respect to handle and appearance without loss offabric wettability. The most important effects of biopolishing can becharacterised by less fuzz and pilling, increased gloss/luster, improvedfabric handle, increased durable softness and improved water absorbency.

Biopolishing usually takes place in the wet processing of themanufacture of knitted and woven fabrics. Wet processing comprises suchsteps as e.g. desizing, scouring, bleaching, washing, dying/printing andfinishing. During each of these steps, the fabric can be subjected tomechanical action.

However, since the cellulolytic enzymes catalyse hydrolysis of thecellulosic fibre surface, the enzymatic action will eventually result ina weight loss of fibre or fabric. Even though the biopolishing iscarried out in such a way so as to obtain a controlled, partialhydrolysis of the fibre surface, a proper polishing effect withoutexcessive loss of fabric strength has hitherto been obtained at a weightloss of fabric of 3-5 w/w %. Such a weight loss is undesirable for thetextile industry and, for economical reasons, makes the biopolishingprocess less desirable.

Thus, it is the object of the present invention to provide a method forobtaining a cellulosic textile fabric with strongly reduced tendency topilling formation but without substantial weight loss of fabric.

SUMMARY OF THE INVENTION

Surprisingly, it has been found that it is possible to obtain acellulosic textile fabric having a strongly reduced tendency to pillingformation at a significantly reduced weight loss by subjecting thefabric to a biopolishing process, preferably using monocomponentcellulases.

Accordingly, the method of the invention comprises treating acellulose-fibre-containing textile fabric with a cellulase capable ofperforming a partial hydrolysis of the fibre surface corresponding to aweight loss of less than 2 w/w %, based on the untreated cellulosictextile fabric, or corresponding to a weight loss of less than about 2%,calculated as the difference, in terms of percentage, of the weight lossof the cellulase treated textile fabric and the weight loss of thetextile fabric treated without cellulase (blank).

DETAILED DESCRIPTION OF THE INVENTION

The fabric

In the present context, the terms "cellulosic textile fabric" and"cellulose-fibre-containing textile fabric" are intended to indicate anytype of fabric, in particular woven or knitted fabric, prepared from acellulose-containing material, containing cellulose or cellulosederivatives, e.g. from wood pulp, and cotton. Also, in the presentcontext, the term "fabric" is intended to include garments and othertypes of processed fabrics. Examples of cellulosic textile fabric iscotton, viscose (rayon); lyocell; flax (linen); all blends of viscose,cotton or lyocell with other fibers such as polyester; viscose/cottonblends, lyocell/cotton blends, viscose/wool blends, lyocell/wool blends,cotton/wool blends; flax (linen), ramie and other fabrics based oncellulose fibers, including all blends of cellulosic fibers with otherfibers such as wool, polyamide, acrylic and polyester fibers, e.g.viscose/cotton/polyester blends, wool/cotton/polyester blends,flax/cotton blends etc.

In the present context, the term "strongly reduced tendency to pillingformation" is intended to mean a permanent (and excellent) resistance toformation of pills on the surface of the treated (biopolished) fabricsurface in comparison with fabric which has not been subjected to themethod of the present invention. The tendency to pilling formation maybe tested according to the Swiss norm SN 198525, published in 1990 bySchweizerische Normen-Vereinigung, Kirchenweg 4, Postfach, CH-8032Zurich, Switzerland, which describes a test of pilling-resistance fortextiles which in turn is based on the Swiss norms SNV 95 150(Textiles--Standard climatic conditions and test conditions for thephysical tests under standard climate conditions) and SN 198 529(Testing of textiles--"Scheuerfestigkeit"--Martindale method). Theresults of the test is expressed in terms of "pilling notes" which is arating on a scale from pilling note 1 (heavy pill formation) to pillingnote 5 (no or very little pill formation), allowing 1/2 pilling notes.

In a preferred embodiment of the present invention, the method providesa textile fabric preferably having a pilling note of at least 4, morepreferably of at least 4.5, especially of 5, measured according to SN198525 (1990).

In another preferred embodiment, the method of the invention provides atextile fabric having rating which is at least 1, preferably at least 2,especially at least 3, pilling note(s) higher than of the corrspondinguntreated textile fabric; the absolute pilling notes being measuredaccording to SN 198525 (1990).

According to the method of the invention, the partial hydrolysis of thefibre surface corresponds to a weight loss of less than about 2 w/w %,preferably a weight loss of less than about 1.8 w/w %, more preferablyof less than about 1.5 w/w %.

The weight loss is determined under controlled conditions, i.e.according to SNV 95150, vide supra. The weight loss is expressed as thedifference, in terms of percentage, of the weight loss of the cellulasetreated textile fabric and the weight loss of the textile fabric treatedwithout cellulase (blank).

The process

As mentioned above, cellulase treatment of the fabric may be carried outsimultaneously with other fabric manufacturing procedures, e.g.desizing, or after the bleaching of the fabric.

It is to be understood that the method of the invention can be carriedout in any conventional wet textile processing step, preferably afterthe desizing or bleaching of the textile fabric, either simultanouslywith a conventional (well-known) process step or as an additionalprocess step. The method will typically be accomplished in high-speedcircular systems such as jet-overflow dyeing machines, high-speedwinches and jiggers. An example of a useful High-speed system is the"Aero 1000" manufactured by Biancalani, Italy. Alternatively, the methodcan be accomplished in a two-step biopolishing process, e.g. asdisclosed in the International Patent Application published as WO93/20278, wherein the first step is a separate cellulase treatment whichis carried out essentially without mechanical treatment, and followed bya second step wherein the fabric is subjected to a mechanical treatment.This cellulase treatment can be carried out in a J-Box, on a Pad-Roll orin a Pad-Bath.

Cellulase treatment according to the present invention and desizing arereconcilable processes that can be conducted at the same conditions,i.e. pH, temperature, dosage/time ratio, etc. By performing theseprocesses simultaneously, the overall fabric manufacturing processbecomes shortened. Such time saving arrangements are a major benefit ofthe process of the invention.

Enzyme dosage greatly depends on the enzyme reaction time, i.e. arelatively short enzymatic reaction time necessitates a relativelyincreased enzyme dosage, and vice versa. In general, enzyme dosage maybe stipulated in accordance with the reaction time available. In thisway cellulase treatment of the fabric according to the present inventioncan be brought into conformity with e.g. the desizing conditions, if forinstance these two reactions are to be carried out simultaneously.

An enzyme dosage/time ratio similar to what is known from conventionalbiopolishing may be used. Preferred enzyme dosages are from about 100 toabout 100,000 ECU/kg fabric, more preferably from about 500 to about20,000 ECU/kg fabric, especially from about 1000 to about 5,000 ECU/kgfabric.

Typically, the reaction time is from about 10 minutes to about 4 hours,preferably from about 20 minutes to about 2 hours but the reaction canbe carried out for any period of time between about 1 minute and about24 hours, in dependence of the specific type of processing equipment.

The method of the invention may be carried out in the presence ofcertain components which can be added to the cellulase, i.e. theformulated cellulase composition, or separately to the wash liquorwherein the enzyme treatment takes place. Examples of such componentsinclude a stabilizer, a wetting agent, a buffer and a dispersing agent.The stabilizer may be an agent stabilizing the cellulolytic enzyme.

The wetting agent serves to improve the wettability of the fibre wherebya rapid and even desizing may be obtained. The wetting agent ispreferably of an oxidation stable type.

The buffer may suitably be a phosphate, borate, citrate, acetate,adipate, triethanolamine, monoethanolamine, diethanolamine, carbonate(especially alkali metal or alkaline earth metal, in particular sodiumor potassium carbonate, or ammonium and HCl salts), diamine, especiallydiaminoethane, imidazole, or amino acid buffer. Preferably, the bufferis a mono-, di-, or triethanolamine buffer.

The dispersing agent may suitably be selected from nonionic, anionic,cationic, ampholytic or zwitterionic surfactants. More specifically, thedispersing agent may be selected from carboxymethylcellulose,hydroxypropylcellulose, alkyl aryl sulphonates, long-chain alcoholsulphates (primary and secondary alkyl sulphates), sulphonated olefins,sulphated monoglycerides, sulphated ethers, sulphosuccinates,sulphonated methyl ethers, alkane sulphonates, phosphate esters, alkylisothionates, acyl sarcosides, alkyl taurides, fluorosurfactants, fattyalcohol and alkylphenol condensates, fatty acid condensates, condensatesof ethylene oxide with an amine, condensates of ethylene oxide with anamide, block polymers (polyethylene glycol, polypropylene glycol,ethylene diamine condensed with ethylene or propylene oxide), sucroseesters, sorbitan esters, alkyloamides, fatty amine oxides, ethoxylatedmonoamines, ethoxylated diamines, ethoxylated polyamines, ethoxylatedamine polymers and mixtures thereof.

Preferably, the dispersing agent is an ethoxylated fatty acid ester or anonylphenyl polyethyleneglycol ether.

Further, the method of the invention may be carried out in the presenceof a conventional antiredepostion agent, e.g. polymeric agents such aspolyvinylpyrrolidone (PVP), carboxymethylcellulose (CMC), andpolyacrylates.

The enzyme

In the present context, the term "cellulase" or "cellulolytic enzyme"refers to an enzyme which catalyses the degradation of cellulose toglucose, cellobiose, triose and other cellooligosaccharides.

In the present context the term "enzyme" or "cellulase enzyme" isunderstood to include a mature protein or a precursor form thereof aswell to a functional fragment thereof which essentially has the activityof the full-length enzyme. Furthermore, the term "enzyme" is intended toinclude homologues or analogues of said enzyme. Such homologues comprisean amino acid sequence exhibiting a degree of identity of at least 60%with the amino acid sequence of the parent enzyme, i.e. the parentcellulase. The degree of identity may be determined by conventionalmethods, see for instance, Altshul et al., Bull. Math. Bio. 48: 603-616,1986, and Henikoff and Henikoff, Proc. Natl. Acad. Sci. USA 89:10915-10919, 1992. Briefly, two amino acid sequences are aligned tooptimize the alignment scores using a gap opening penalty of 10, a gapextension penalty of 1, and the "blosum 62" scoring matrix of Henikoffand Henikoff, supra.

Alternatively, the homologue or analogue of the enzyme may be oneencoded by a nucleotide sequence hybridizing with an oligonucleotideprobe prepared on the basis of the nucleotide sequence or an amino acidsequence under the following conditions: presoaking in 5×SSC andprehydbridizing for 1 hr. at about 40° C. in a solution of 20%formamide, 5×Denhardt's solution, 50 mM sodium phosphate, pH 6.8, and 50μg denatured sonicated calf thymus DNA, followed by hybridization in thesame solution supplemented with 100 μM ATP for 18 hrs. at about 40° C.,followed by a wash in 0.4×SSC at a temperature of about 45° C.

Molecules to which the oligonucleotide probe hybridizes under theseconditions are detected using standard detection procedures (e.g.Southern blotting).

Homologues of the present enzyme may have one or more amino acidsubstitutions, deletions or additions. These changes are preferably of aminor nature, that is conservative amino acid substitutions that do notsignificantly affect the folding or activity of the protein, smalldeletions, typically of one to about 30 amino acids; small amino- orcarboxyl-terminal extensions, such as an amino-terminal methionineresidue, a small linker peptide of up to about 20-25 residues, or asmall extension that facilitates purification, such as a poly-histidinetract, an antigenic epitope or a binding domain. See in general Ford etal., Protein Expression and Purification 2: 95-107, 1991. Examples ofconservative substitutions are within the group of basic amino acids(such as arginine, lysine, histidine), acidic amino acids (such asglutamic acid and aspartic acid), polar amino acids (such as glutamineand asparagine), hydrophobic amino acids (such as leucine, isoleucine,valine), aromatic amino acids (such as phenylalanine, tryptophan,tyrosine) and small amino acids (such as glylocine, alanine, serine,threonine, methionine).

It will be apparent to persons skilled in the art that suchsubstitutions can be made outside the regions critical to the functionof the molecule and still result in an active enzyme. Amino acidsessential to the activity of the enzyme of the invention, and thereforepreferably not subject to substitution, may be identified according toprocedures known in the art, such as site-directed mutagenesis oralanine-scanning mutagenesis (Cunningham and Wells, Science 244,1081-1085, 1989). In the latter technique mutations are introduced atevery residue in the molecule, and the resultant mutant molecules aretested for cellulolytic activity to identify amino acid residues thatare critical to the activity of the molecule. Sites of ligand-receptorinteraction can also be determined by analysis of crystal structure asdetermined by such techniques as nuclear magnetic resonance,crystallography or photoaffinity labelling. See, for example, de Vos etal., Science 255: 306-312, 1992; Smith et al., J. Mol. Biol. 224:899-904, 1992; Wlodaver et al., FEBS Lett. 309: 59-64, 1992.

The homologue may be an allelic variant, i.e. an alternative form of agene that arises through mutation, or an altered enzyme encoded by themutated gene, but having substantially the same activity as the enzymeof the invention. Hence mutations can be silent (no change in theencoded enzyme) or may encode enzymes having altered amino acidsequence.

The homologue of the present enzyme may also be a genus or specieshomologue, i.e. an enzyme with a similar activity derived from anotherspecies.

A homologue of the enzyme may be isolated by preparing a genomic or cDNAlibrary of a cell of the species in question, and screening for DNAsequences coding for all or part of the homologue by using syntheticoligonucleotide probes in accordance with standard techniques, e.g. asdescribed by Sambrook et al., Molecular Cloning:A Laboratory Manual,2nd. Ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1989,or by means of polymerase chain reaction (PCR) using specific primers asdescribed by Sambrook et al., supra.

Preferably, the cellulolytic enzyme to be used in the method of theinvention is a monocomponent (recombinant) cellulase, i.e. a cellulaseessentially free from other proteins or cellulase proteins. Arecombinant cellulase component may be cloned and expressed according tostandard techniques conventional to the skilled person.

In a preferred embodiment of the invention, the cellulase to be used inthe method is an endoglucanase (EC 3.2.1.4), preferably a monocomponent(recombinant) endoglucanase.

Preferably, the cellulase is a microbial cellulase, more preferably abacterial or fungal cellulase. Examples of bacterial cellulases arecellulases derived from or producible by bacteria from the group ofgenera consisting of Pseudomonas or Bacillus lautus.

The cellulase or endoglucanase may be an acid, a neutral of an alkalinecellulase or endoglucanase, i.e. exhibiting maximum cellulolyticactivity in the acid, neutral of alkaline range, respectively.

Accordingly, a useful cellulase is an acid cellulase, preferably afungal acid cellulase, more preferably a fungal acid cellulase enzymewith substantial cellulolytic activity at acidic conditions which isderived from or producible by fungi from the group of genera consistingof Trichoderma, Actinomyces, Myrothecium, Aspergillus, and Botrytis.

A preferred useful acid cellulase is derived from or producible by fungifrom the group of species consisting of Trichoderma viride, Trichodermareesei, Trichoderma longibrachiatum, Myrothecium verrucaria, Aspergillusniger, Aspergillus oryzae, and Botrytis cinerea.

Another useful cellulase or endoglucanase is a neutral or alkalinecellulase, preferably a fungal neutral or alkaline cellulase, morepreferably a fungal alkaline cellulase or endoglucanase with substantialcellulolytic activity at alkaline conditions which is derived from orproducible by fungi from the group of genera consisting of Aspergillus,Penicillium, Myceliophthora, Humicola, Irpex, Fusarium, Stachybotrys,Scopulariopsis, Chaetomium, Mycogone, Verticillium, Myrothecium,Papulospora, Gliocladium, Cephalosporium and Acremonium.

A preferred alkaline cellulase is derived from or producible by fungifrom the group of species consisting of Humicola insolens, Fusariumoxysporum, Myceliopthora thermophile, or Cephalosporium sp., preferablyfrom the group of species consisting of Humicola insolens, DSM 1800,Fusarium oxysporum, DSM 2672, Myceliopthora thermophile, CBS 117.65, orCephalosporium sp., RYM-202.

A preferred example of a native or parent cellulase is an alkalineendoglucanase which is immunologically reactive with an antibody raisedagainst a highly purified .sup.˜ 43 kD endoglucanase derived fromHumicola insolens, DSM 1800, or which is a derivative of the .sup.˜ 43kD endoglucanase exhibiting cellulase activity. A preferredendoglucanase component has the amino acid sequence enclosed as SEQ IDNo. 1 which is also disclosed in the International Patent Applicationpublished as WO 91/17243, SEQ ID#2, which is hereby incorporated byreference. Another preferred endoglucanase component is the core enzymecorresponding to the amino acid sequence enclosed as SEQ ID No. 1, buthaving the amino acid sequence corresponding to position 1-213, i.e.truncated at position 213. It is contemplated that other usefulendoglucanases are enzymes having amino acid sequences corresponding tothe amino acid sequence enclosed as SEQ ID No. 1, but which aretruncated, preferably genetically truncated, at any position betweenposition 213 and position 247 of the SEQ ID No. 1, i.e. having an aminoacid sequence consisting of between 213 and 247 amino acid residues.

Other examples of useful cellulases are variants having, as a parentcellulase, a cellulase of fungal origin, e.g. a cellulase derivable froma strain of the fungal genus Humicola, Trichoderma or Fusarium. Forinstance, the parent cellulase may be derivable from a strain of thefungal species H. insolens, Trichoderma reesei or F. oxysporum,preferably the .sup.˜ 43 kD endoglucanase derived from Humicolainsolens, DSM 1800, or is a functional analogue of any of said parentcellulases which

i) comprises an amino acid sequence being at least 60% homologous withthe amino acid sequence of the parent cellulase,

ii) reacts with an antibody raised against the parent cellulase, and/or

iii) is encoded by a DNA sequence which hybridizes with the same probeas a DNA sequence encoding the parent cellulase.

Property i) of the analogue is intended to indicate the degree ofidentity between the analogue and the parent cellulase indicating aderivation of the first sequence from the second. In particular, apolypeptide is considered to be homologous to the parent cellulase if acomparison of the respective amino acid sequences reveals an identity ofgreater than about 60%, such as above 70%, 80%, 85%, 90% or even 95%.Sequence comparisons can be performed via known algorithms, such as theone described by Lipman and Pearson (1985).

The additional properties ii) and iii) of the analogue of the parentcellulase may be determined as follows:

Property ii), i.e. the immunological cross reactivity, may be assayedusing an antibody raised against or reactive with at least one epitopeof the parent cellulase. The antibody, which may either be monoclonal orpolyclonal, may be produced by methods known in the art, e.g. asdescribed by Hudson et al., 1989. The immunological cross-reactivity maybe determined using assays known in the art, examples of which areWestern Blotting or radial immunodiffusion assay, e.g. as described byHudson et al., 1989.

The oligonucleotide probe used in the characterization of the analoguein accordance with property iii) defined above, may suitably be preparedon the basis of the full or partial nucleotide or amino acid sequence ofthe parent cellulase. The hybridization may be carried out under anysuitable conditions allowing the DNA sequences to hybridize. Forinstance, such conditions are hybridization under specified conditions,e.g. involving presoaking in 5×SSC and prehybridizing for 1h at ˜40° C.in a solution of 20% formamide, 5×Denhardt's solution, 50 mM sodiumphosphate, pH 6.8, and 50 μg of denatured sonicated calf thymus DNA,followed by hybridization in the same solution supplemented with 100 μMATP for 18h at ˜40° C., or other methods described by e.g. Sambrook etal., 1989.

Examples of useful cellulase variants are variants of the 43 kDendoglucanase derived from or producible by Humicola insolens, DSM 1800,SEQ ID NO:1, modified by substitution of one or more amino acid residuesin one or more of the positions 8, 55, 58, 62, 67, 132, 147, 162, 221,222, 223, 280; and optionally further modified by truncation, preferablygenetically truncation, at any position from position 213.

Preferred cellulase variants are variants of the 43 kD endoglucanasederived from or producible by Humicola insolens, DSM 1800, SEQ ID NO:1,modified by substitution of one or more amino acid residues as follows:

Y8F

S55E/D

D58A/S/N

W62E

D67R/N

F132A/D/E/G

Y147S

A162P

V221S

N222S

Q223T

Y280F.

Surprisingly, it has been found that, in case of using an alkalineendoglucanase such as the 43 kD H. insolens, DSM 1800, endoglucanase orthe mentioned modified variants thereof, it may be advantageous to carryout the method of the present invention at a pH below about 9,preferably at a pH below 6, more preferably at a pH of from about 4.5 toabout 5.5, especially at a pH of about 5.0.

In the context of this invention, cellulase activity can be expressed inECU. Cellulolytic enzymes hydrolyse CMC, thereby increasing theviscosity of the incubation mixture. The resulting reduction inviscosity may be determined by a vibration viscosimeter (e.g. MIVI 3000from Sofraser, France).

Determination of the cellulolytic activity, measured in terms of ECU,may be determined according to the following analysis method (assay):The ECU assay quantifies the amount of catalytic activity present in thesample by measuring the ability of the sample to reduce the viscosity ofa solution of carboxy-methylcellulose (CMC). The assay is carried out at40° C.; pH 7.5; 0.1M phosphate buffer; time 30 min; using a relativeenzyme standard for reducing the viscosity of theCMC(carboxymethylcellulose Hercules 7 LFD) substrate; enzymeconcentration approx. 0.15 ECU/ml. The arch standard is defined to 8200ECU/g.

Although the useful cellulase may be used as such in the method of thepresent invention, it is preferred that it is formulated into a suitablecomposition. Thus, the useful cellulase may be used in the form of agranulate, preferably a non-dusting granulate, a liquid, in particular astabilized liquid, a slurry, or in a protected form. Dust freegranulates may be produced, e.g. as disclosed in U.S. Pat. No. 4,106,991and U.S. Pat. No. 4,661,452 (both to Novo Nordisk A/S) and mayoptionally be coated by methods known in the art.

Liquid enzyme preparations may, for instance, be stabilized by adding apolyol such as e.g. propylene glycol, a sugar or sugar alcohol or aceticacid, according to established methods. Other enzyme stabilizers arewell known in the art. Protected enzymes may be prepared according tothe method disclosed in EP 238 216.

The performance of enzymes greatly depends on process conditions such ase.g. pH and temperature. In accomplishing the process of this invention,of course, factors such as e.g. pH-dependent performance and thermalstability should be taken into consideration in the choice of cellulyticenzymes. Other conditions such as e.g. the addition of wetting agents,etc., also depend on the overall process to be performed, as well as theenzyme employed.

The invention is further illustrated by the following non-limitingexample.

EXAMPLE

Apparatus:

The test was carried out in an Atlas LP2 Launder-O-Meter using 2swatches per beaker.

Textile:

Bleached interlock knitted 100% cotton fabric, 205 g/m². The fabric wascut into pieces of a size 14×12 cm (about 3.5 g each) and conditionedovernight at 20° C. and 65% relative humidity under constant conditions.

Enzymes:

A: Reference (Cellusoft L, a commercial acid cellulase preparationproduced and sold by Novo Nordisk A/S, DK-2880 Bagsvaerd, Denmark).

B: 43 kD endoglucanase from Humicola insolens, DSM 1800.

C: Variant of B (substitution D58A)

D: Variant of B (substitution F132D)

E: Variant of B (substitution Y280F)

F: Variant of B (substitution D67R)

G: Variant of B (substitution Y147S)

H: Variant of B (substitution S55E)

J: Variant of B (substitutions Y8F, W62E, A162P, V221S, N222S, Q223T)

K: Variant of B (substitution Y147N)

Experimental conditions:

(Launder-O-Meter biopolishing)

4 beakers (8 swatches) were used for each test.

    ______________________________________    Liquor ratio    1:20    Liquor volume  140 ml    Abrasive agent  20 steel balls (d = 14 mm, 11 g)    pH              5.0    Buffer          1 g/l acetate    Time            60 min    Temperature     55° C.    ______________________________________

Inactivation:

Each test was terminated by washing all the swatches at 70° C. followedby rinsing three times in a standard European home laundry machine, AEGOko-Lavamat 665.

Drying:

The swatches were air dried and conditioned overnight at 20° C. and 65%relative humidity.

Tests:

The commercial enzyme preparation A was tested in 4 dosages in the range0-4.0 w/w %, based on the weight of the textile.

Each of the enzyme preparations B-K were tested in 4 dosages in therange 0-5.0 ECU/g textile.

Results:

The following parameters were measured/calculated:

* Weight loss, in terms of percentage, of the weight loss of thecellulase treated textile fabric and the weight loss of the textilefabric treated without cellulase (blank).

* Pilling note (PN), measured according to SN 198525 (1990) using aMartindale Pilling Tester at 500 revolutions.

The pilling note of the untreated textile as well as of the textiletreated without cellulase (blank) was 1.

The following table shows the measured weight loss corresponding to aresulting pilling note of 4.5 of the cellulase treated textile.

                  TABLE    ______________________________________    Enzyme      Weight loss (Δ%)    ______________________________________    A (ref.)    5.6    B           2.0    C           1.3    D           1.3    E           2.0    F           1.7    G           1.2    H           1.0    J           1.2    K           1.5    ______________________________________

    __________________________________________________________________________    #             SEQUENCE LISTING    - (1) GENERAL INFORMATION:    -    (iii) NUMBER OF SEQUENCES: 1    - (2) INFORMATION FOR SEQ ID NO:1:    -      (i) SEQUENCE CHARACTERISTICS:    #acids    (A) LENGTH: 305 amino              (B) TYPE: amino acid              (D) TOPOLOGY: linear    -     (ii) MOLECULE TYPE: protein    -     (vi) ORIGINAL SOURCE:    #insolens (A) ORGANISM: Humicola              (B) STRAIN: DSM 1800    -           (xi) SEQUENCE DESCRIPTION: - # SEQ ID NO:1:    - Met Arg Ser Ser Pro Leu Leu Pro Ser Ala Va - #l Val Ala Ala Leu Pro    10    - Val Leu Ala Leu Ala Ala Asp Gly Arg Ser Th - #r Arg Tyr Trp Asp Cys    #                 10    - Cys Lys Pro Ser Cys Gly Trp Ala Lys Lys Al - #a Pro Val Asn Gln Pro    #             25    - Val Phe Ser Cys Asn Ala Asn Phe Gln Arg Il - #e Thr Asp Phe Asp Ala    #         40    - Lys Ser Gly Cys Glu Pro Gly Gly Val Ala Ty - #r Ser Cys Ala Asp Gln    #     55    - Thr Pro Trp Ala Val Asn Asp Asp Phe Ala Le - #u Gly Phe Ala Ala Thr    # 75    - Ser Ile Ala Gly Ser Asn Glu Ala Gly Trp Cy - #s Cys Ala Cys Tyr Glu    #                 90    - Leu Thr Phe Thr Ser Gly Pro Val Ala Gly Ly - #s Lys Met Val Val Gln    #            105    - Ser Thr Ser Thr Gly Gly Asp Leu Gly Ser As - #n His Phe Asp Leu Asn    #       120    - Ile Pro Gly Gly Gly Val Gly Ile Phe Asp Gl - #y Cys Thr Pro Gln Phe    #   135    - Gly Gly Leu Pro Gly Gln Arg Tyr Gly Gly Il - #e Ser Ser Arg Asn Glu    140                 1 - #45                 1 - #50                 1 -    #55    - Cys Asp Arg Phe Pro Asp Ala Leu Lys Pro Gl - #y Cys Tyr Trp Arg Phe    #               170    - Asp Trp Phe Lys Asn Ala Asp Asn Pro Ser Ph - #e Ser Phe Arg Gln Val    #           185    - Gln Cys Pro Ala Glu Leu Val Ala Arg Thr Gl - #y Cys Arg Arg Asn Asp    #       200    - Asp Gly Asn Phe Pro Ala Val Gln Ile Pro Se - #r Ser Ser Thr Ser Ser    #   215    - Pro Val Asn Gln Pro Thr Ser Thr Ser Thr Th - #r Ser Thr Ser Thr Thr    220                 2 - #25                 2 - #30                 2 -    #35    - Ser Ser Pro Pro Val Gln Pro Thr Thr Pro Se - #r Gly Cys Thr Ala Glu    #               250    - Arg Trp Ala Gln Cys Gly Gly Asn Gly Trp Se - #r Gly Cys Thr Thr Cys    #           265    - Val Ala Gly Ser Thr Cys Thr Lys Ile Asn As - #p Trp Tyr His Gln Cys    #       280    - Leu    __________________________________________________________________________

We claim:
 1. A method for obtaining a cellulosic textile fabric having astrongly reduced tendency to pilling formation, the method comprisingtreating a cellulose-fiber-containing textile fabric with a cellulasecapable of performing a partial hydrolysis of the fiber surfacecorresponding to a weight loss of less than 2 w/w % based on theuntreated cellulosic textile fabric, wherein the cellulase comprises avariant of a 43 kD endoglucanase derived from Humicola insolens, DSM1800, said variant being modified by:(a) substitution of one or moreamino acid residues at one or more of the positions 8, 55, 58, 62, 67,132, 147, 162, 221, 222, and 223 of SEQ ID NO:1; or (b) truncationbetween position 213 to position
 247. 2. The method according to claim1, wherein the pilling formation corresponds to a pilling note of atleast
 4. 3. The method according to claim 1, wherein the textile fabriccontains cellulose fibers selected from the group consisting of cotton,viscose, lyocell, all blends of viscose, cotton or lyocell with otherfibers such as polyester, viscose/cotton blends, lyocell/cotton blends,viscose/wool blends, lyocell/wool blends, cotton/wool blends, flax,ramie and other fabrics based on cellulose fibers, including all blendsof cellulosic fibers with other fibers such as wool, polyamide, acrylicand polyester fibers.
 4. A method according to claim 1, wherein thecellulase is a monocomponent cellulase.
 5. The method according to claim1, wherein the treatment is carried out at a pH below about
 9. 6. Themethod according to claim 1, wherein said substitutions are selectedfrom the group consisting of Y8F, S55E/D, D58A/S/N, W62E, D67R/N,F132A/D/E/G, Y147S, A162P, V221S, N222S, and Q223T.
 7. The methodaccording to claim 1, wherein the treatment is carried out in any wetprocessing stage of a conventional textile fabric manufacturing process.8. The method according to claim 7, wherein the treatment isaccomplished in high-speed circular systems.
 9. The method according toclaim 7, wherein the treatment is accomplished in a J-Box, on a Pad-Rollor in a Pad-Bath during a two-step biopolishing process.
 10. The methodof claim 2, wherein the pilling note is at least 4.5.
 11. The method ofclaim 5, wherein the pH is below
 6. 12. The method of claim 11, whereinthe pH is about 4.5 to about 5.5.
 13. The method of claim 12, whereinthe pH is about 5.0.